Private businesses added 158,000 jobs last month, considerably below analysts' expectations. Analysts had predicted the report would show 205,000, and it will force economists to pare estimates for the government's labor report, due Friday.

"The job market continues to improve, but in fits and starts," says Mark Zandi, chief economist at Analytics.

Stocks took a rare pause after the data's release. Dow Jones industrial average futures fell 4 points to 14,580. The S&P 500 and Nasdaq composite maintained their early morning gains. The S&P 500 ticked up 0.5 point to 1,565, and the Nasdaq climbed 2 points to 2,814.75.

Despite recent declines in unemployment over the past year, the labor market is growing far slower than economists would like. March could be the second consecutive in which the economy grew only about 150,000 jobs, almost half the figure that economists say the country must add each month to make significant headway in the recovery.